• Mar 23rd 2010, 01:17 PM
eleahy
hey there i know it was a while ago but your answer seems clear any chance you know how to get the invertible and diagonal of a 3x3 matrix?? i've got the two eigenvalues and eigenvectors already!!!!

(just incase you need to know)
eigenvalues being 2 and -3
eigenvectors being (-1 over 3 over 1) for 2 and the second one is (1 over -1 over 2) for -3!

the matrix is a 3x3 its(3 4 -1
-1 -2 1
3 9 0)

dunno do you need to know but i said id write it anyway thanks a lot!!!!!!11
• May 22nd 2010, 03:05 PM
dwsmith
Quote:

Originally Posted by eleahy
hey there i know it was a while ago but your answer seems clear any chance you know how to get the invertible and diagonal of a 3x3 matrix?? i've got the two eigenvalues and eigenvectors already!!!!

(just incase you need to know)
eigenvalues being 2 and -3
eigenvectors being (-1 over 3 over 1) for 2 and the second one is (1 over -1 over 2) for -3!

the matrix is a 3x3 its(3 4 -1
-1 -2 1
3 9 0)

dunno do you need to know but i said id write it anyway thanks a lot!!!!!!11

You can't diagonalize a matrix with an eigenspace less than n. n=3 here. Also, you eigenvector when $\lambda=2$ is $x_3\begin{bmatrix}
-1\\
1\\
3
\end{bmatrix}$